Currently, the LED-based T8/T5 tubes are emerging as a replacement for traditional fluorescent lamps which can be widely used in the application sites, such as offices, shops and homes. The LED lighting device of the prior art generally includes a LED aluminum based board/printed circuit board, a LED lighting source, a transparent cover or a scattering cover, a heat sink and a heat conducting medium (for example, a heat conducting silicon). The printed circuit board is fixed to the heat sink typically by a plurality of screws in order to obtain perfect heat conductivity between the printed circuit board and the heat sink. Since the distance between the electrical element and the circuit of the printed circuit board and the screws is restricted critically, the plurality of screws used on the circuit board can affect the routing design of the circuit seriously. In addition, the use of the plurality of screws results in additional difficulties for the manufacture and maintenance of the products.
In the prior art, another solution is to connect the printed circuit board to the heat sink by means of a type of adhesive heat conducting glue. But this is not practical, because the T8/T5 tubes are relatively longer, the adhesive glue may cause reliability problems due to the thermal expansion during using, for example, the potential separation or curving of the printed circuit board and the heat sink.